1. Field of the Invention
This invention relates to surveillance systems. Specifically, the invention relates to a video-based surveillance system that monitors a wide range of area by fusing the data from multiple surveillance cameras.
2. Related Art
Some state of art intelligent video surveillance (IVS) system can perform content analysis on the image view of each camera. Based on user defined rules or policies, IVS systems can automatically detect potential threats by detecting, tracking and analyzing the targets in the scene. While this type of system has been proven to be very effective and helpful for video surveillance applications, its capability may be constrained by the fact that an isolated single camera can only monitor a limited area. Further, conventional systems usually do not remember past targets, especially when the past targets appeared to act normally, thus a conventional system cannot detect the threats which can only be inferred by repeatable actions.
Now, security needs demand much more capabilities from IVS. For example, a nuclear power plant may have more than ten intelligent surveillance cameras monitoring the surroundings of one of its critical facilities. It may be desirable to receive an alert when there may be some target (e.g., a human or vehicle) loitering around the site for more than fifteen minutes, or when the same target approaches the site more than three times in a day. The conventional individual camera system would fail to detect the threats because a target of interest may loiter at the site for more than an hour, but not stay in any single camera view for more than two minutes, or the same suspect target might approach the site five times in a day but from different directions.
What may be needed then may be an improved IVS system that overcomes shortcomings of conventional solutions.